/*
 * JFFS2 -- Journalling Flash File System, Version 2.
 *
 * Copyright (C) 2001-2003 Red Hat, Inc.
 *
 * Created by Dominic Ostrowski <dominic.ostrowski@3glab.com>
 * Contributors: David Woodhouse, Nick Garnett, Richard Panton.
 *
 * For licensing information, see the file 'LICENCE' in this directory.
 *
 * $Id: flashio.c,v 1.1 2003/11/26 14:09:29 dwmw2 Exp $
 *
 */

#include <linux/kernel.h>
#include "nodelist.h"

int jffs2_flash_write(struct jffs2_sb_info * c,
                uint32_t offset, const size_t size,
                size_t * return_size, unsigned char *buffer)
{
    return c->mtd->write(c->mtd, offset, size, return_size, (char *)buffer);/*lint !e115 !e64 !e119*/
}

int jffs2_flash_erase(struct jffs2_sb_info * c,
                struct jffs2_eraseblock * jeb)
{
        return ENOERR;
}

int jffs2_flash_direct_writev(struct jffs2_sb_info *c,
                const struct iovec *vecs, unsigned long count, loff_t to,
                size_t * retlen)
{
        unsigned long i;
        size_t totlen = 0, thislen;
        int ret = 0;

        for (i = 0; i < count; i++)
        {
                // writes need to be aligned but the data we're passed may not be
                // Observation suggests most unaligned writes are small, so we
                // optimize for that case.

                if (((vecs[i].iov_len & (sizeof(int) - 1))) ||
                (((unsigned long) vecs[i].iov_base & (sizeof(unsigned long) - 1))))
                {
                        // are there iov's after this one? Or is it so much we'd need
                        // to do multiple writes anyway?
                        if ((i + 1) < count || vecs[i].iov_len > 256)
                        {
                                // cop out and malloc
                                unsigned long j;
                                size_t sizetomalloc = 0, totvecsize = 0;
                                char *cbuf, *cbufptr;

                                for (j = i; j < count; j++)
                                  totvecsize += vecs[j].iov_len;

                                // pad up in case unaligned
                                sizetomalloc = totvecsize + sizeof(int) - 1;
                                sizetomalloc &= ~(sizeof(int) - 1);
                                cbuf = (char *) malloc(sizetomalloc);
                                // malloc returns aligned memory
                                if (!cbuf)
                                {
                                        ret = -ENOMEM;
                                        goto writev_out;
                                }
                                cbufptr = cbuf;
                                for (j = i; j < count; j++)
                                {
                                        (void)memcpy_s(cbufptr, vecs[j].iov_len, vecs[j].iov_base, vecs[j].iov_len);
                                        cbufptr += vecs[j].iov_len;
                                }
                                ret = jffs2_flash_write(c, to, sizetomalloc, &thislen,
                                                (unsigned char *) cbuf);
                                if (thislen > totvecsize) // in case it was aligned up
                                        thislen = totvecsize;
                                totlen += thislen;
                                free(cbuf);
                                goto writev_out;
                        }
                        else
                        {
                                // otherwise optimize for the common case
                                int buf[256/sizeof(int)]; // int, so int aligned
                                size_t lentowrite;

                                lentowrite = vecs[i].iov_len;
                                // pad up in case its unaligned
                                lentowrite += sizeof(int) - 1;
                                lentowrite &= ~(sizeof(int) - 1);
                                ret = memcpy_s(buf, sizeof(buf), vecs[i].iov_base, lentowrite);
                                if(ret != EOK)
                                    goto writev_out;

                                ret = jffs2_flash_write(c, to, lentowrite, &thislen,
                                                (unsigned char *) &buf[0]);
                                if (thislen > vecs[i].iov_len)
                                        thislen = vecs[i].iov_len;
                        }
                }
                else
                {
                        ret = jffs2_flash_write(c, to, vecs[i].iov_len, &thislen,
                                vecs[i].iov_base);
                }
                totlen += thislen;
                if (ret || thislen != vecs[i].iov_len) break;
                to += vecs[i].iov_len;
        }

writev_out:
        if (retlen) *retlen = totlen;

        return ret;
}
